From the specification data on the previous page, the conversion time (tDCONV) of the D/A in an H8S/2148A device is 10µs maximum, with a 20pF load. This diagram shows the relative timing between the instant when the user writes to the D/A register and the time when the output changes. One point that must be emphasized here is: users do not have to continuously write the same value to the D/A Data Register (DADR) to “refresh” the output. The output will remain at a constant level until new data is written to the register. Customers might wonder why the datasheet specifies the load capacitance on the D/A output. That’s because there is an analog connection to the output of the converter. Any capacitive loading will affect the time it takes to complete the conversion because the drive current from the D/A circuit is limited.